A device and process for producing chlorinated high polymer

Abstract

The invention provides an apparatus and process for producing a chlorinated high polymer. According to the invention, plasma or ultraviolet lamps are used to excite chlorine gas so as to prepare the chlorinated high polymer. Under the action of fluidization gas and fluidization-aiding gas, the chlorinated high polymer is produced by a pretreated high polymer under the excitation of plasma or ultraviolet light through stirring and heating, wherein the fluidization gas is composed of pretreated chlorine gas and hydrogen chloride gas or inert gas in proportion. Due to the gradient control of the chlorination reaction heat, two or more fluidized bed reactors are installed in the apparatus and connected by risers which are easy to adjust length and each of which is internally provided with an ultraviolet light tube or a plasma discharging device, wherein the risers are mainly used for exciting reaction gas, prolonging gas activation time, dissipating heat and promoting uniform reaction. The high polymer and the reaction gas circulate between the two fluidized bed reactors through the risers, so the phenomenon of uneven chlorination caused by backmixing occurred in single-bed fluidization can be avoided and the phenomenon of non-smooth movement of materials caused by the height restriction of a high polymer layer can be overcome; and thus, reaction heat is better controlled, and the high polymer meets the requirement of uniform chlorine content.

Description

technical field [0001] The invention belongs to the field of chemical production and manufacturing, in particular to a device and process for producing chlorinated high polymers. Background technique [0002] The existing chlorinated polymer production processes mainly include solution method, aqueous phase suspension method, and gas-solid phase method. Since the production of chlorinated polymers by the solvent method will produce a large amount of organic solvents that are harmful to the human body and seriously damage the ozone layer of the atmosphere, they have been gradually eliminated by domestic and foreign manufacturers. The production process of aqueous phase suspension method is the main method for most enterprises to produce chlorinated polyethylene and chlorinated polyvinyl chloride. However, the production process of the aqueous phase suspension method requires a large amount of water resources as a carrier, which causes great waste and pollution of water sourc...

AI Technical Summary

Problems solved by technology

Ultraviolet photocatalysis can reduce the reaction temperature with stable energy and low power consumption. Plasma catalysis further reduces the reaction temperature and can catalyze chlorination at room temperature, but the power consumption is high and energy stability is difficult to grasp.

Patent 201010165999.7 proposes a method for preparing chlorinated polyvinyl chloride by using a circulating fluidized bed in a riser reactor through a gas-solid phase method of ultraviolet photocatalysis. The material auxiliary gas path is prone to clogging of the feeding pipe, and the uniformity of the feeding is poor; at the same time, the phenomenon of material back-mixing is prone to occur, and the uniformity of chlorination cannot be guaranteed. Since the reaction is a rapid exothermic process when the chlorination value reaches a certain level, it cannot Efficient transfer of heat

Patent 200910092928.6 "Method and Equipment for Preparing Chlorinated Polyvinyl Chloride in a Low-Temperature Plasma Circulating Fluidized Bed" proposes that the use of low-temperature plasma can simultaneously activate chlorine gas and the surface of polyvinyl chloride, and realize the high-efficiency excitation of polyvinyl chloride chlorination in the down-bed The reaction process, and further realize the surface chlorine to the internal rotation and migration process in the riser and turbulent bed, so that the entire chlorination process is decoupled into two steps of fast and slow, and the production efficiency is significantly better than that of ultraviolet chlorine addition and water phase suspension However, in the down-bed reactor, the material is in a dense phase flow state, the solid-gas ratio is high, and the chlorine free radicals formed after the gas is treated with plasma are less, and the probability of chlorination reaction is small, which increases the equipment maintenance operation , and the utilization rate of the equipment is low, and the relative temperature of the plasma is high, and the middle stage of the reaction is a rapid exothermic reaction, so the heat cannot be effectively transferred

Patent 201110061421.1 "Method and device for continuous production of chlorinated polyvinyl chloride in a low-temperature plasma circulating bed" proposes a method for producing chlorinated polyvinyl chloride by low-temperature plasma catalysis, and realizes rapid chlorination of PVC in a circulating fluidized bed. Groups of fluidized bed reactors are operated in turn to achieve continuous production, which avoids problems such as reduced production efficiency caused by reactor shutdown and unloading; on the other hand, it can avoid shutdown and restart of fans and tail gas treatment devices, saving Energy consumption prolongs the life of the equipment, but there are also problems that the material in the down-bed reactor is in a dense phase flow state, the solid-gas ratio is high, the probability of chlorination reaction is small, the chlorination is uneven, the material is easy to block, back-mix, and the temperature cannot Effective control while increasing the workload of equipment maintenance

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